Method of making packing-rings.



E. R. NORMAN.

METHOD OF MAKING PACKING RINGS.

APPLICATION FILED JUNE 4. I917.

1,292,633, Patented Jan. 28,1919.

X? 17197511 J0 i8 EDWARD R. NORMAN, OF CHICAGO, ILLINOIS.

METHOD OF MAKING PACKING-RINGS.

Specification of Letters Patent.

Patented Jan. 28, 1919.

,, Application filed June 4, 1917. Serial No. 172,604.

To all whom it may concern:

Be it known that I, EDWARD R. NORMAN, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Methods of Making Packing-Rings, of which the following is a specification, reference being had therein to the accompanying drawing.

My invention relates to a new and useful process of making packing rings, which may be used in various organizations as for example on pistons for internal explosion engines, steam engines, high'pressure pumps, elevator cylinders, two cycle and four cycle gas engines, whistles, submarine engines, air brakes, air hammers and air engines.

The primary object of my invention is to provide a one-piece ring which, while flexible and self-adjustable'to wear so that it forms a fluid-tight joint at all times between the parts, as the piston and cylinder, is provided with a circumferentially elongated joint between its ends to insure a leak-proof seal in the ring itself under different relative positions of its ends due to service conditions which may produce movement or displacement of the joint members, and which will not mar or score the cylinder walls. Other objects and advantages will be apparent from a disclosure of the invention.

My invention is illustrated in the accompanying drawings wherein- Figure 1 shows a side view of the original blank from which the ring is made;

Fig. 2 is a View showing the operation of milling one side of the joint as by a top cutter or milling tool;

Fig. 3 is a. view showing the operation of milling the other side of the joint as by a lower cutter or miller, and showing parts for the joint as completed by the operation of the cutters;

Fig. 4 is a. detail plan view of the ring with its joint ascompleted by the cutting:

Fig. 5 is a side view of the ring when closed, and showing the rollers to set the metal of the ring;

Fig. 6 is a detail side view of the ring when expanded in an over-sized cylinder or worn cylinder showing the joint extended but forming a sealed joint;

Fig. 7 is a plan view of the joint when the ring is in closed position;

Fig. 8 is a plan view of the parts in Fig.

6, and Fig. 9 is'a perspective view of the parts in Fig.

In forming my flexible one-piece ring by my process, I first produce by casting or otherwise a ring-shaped blank B of suitable material, such as good gray iron. The shape of this blank is slightly ova-l or elongated, and its size exceeds that of the finished ring in closed position by an amount equal to the amount of material removed at the joint plus shrinkage and turning or grinding. The width of this blanlcsliould exceed the finished ring by an amount equal to shrinkage and turning or grinding. The

oval shape or contour of the blank quay be variously produced. In the present instance the blank B is made as shown in Fig. 1 with the greatest diameter or major axis through the points 5 and 6, and the chords of the arcs 14 and 23 are equally distant from the central points 7 and 8 respectively of thesearcs. The several arcs of the blank are made upon the difi'erent'radii shown in that figure; the arcs from 5 to 2 and from .6 to 3 are on the same side of the major axis of the blank and are made upon radii struck from points on the major axis on opposite sides of its center C and equally offset or distant therefrom; the arcs from 5 to 1 and from 6 to 4 are on the same side of said major axis but on the side thereof opposite to the arcs from 5 to 2 and from 6 to 3. and are made upon radii struck from points on the major axis on opposite sides of its center and equally distant or offset therefrom but. nearer thereto than the points upon which said arcs 5 to 2 and 6 to 3 are struck; the arcs 1 to 4 and 2 to 3 are made upon radu struck from points on opposite sides of the center of the major axis of the blank, and the point upon which the radius of the are 2 to 3 is struck is farther from the center of the major axis than the point upon which the radius of the arcl to 4 is struck, the variations where the radii merge being so slight that. no distortion occurs in the pattern. The result is that in the blank the are from 2 to 3 at the center 7 of which the joint is out is flatter or of less curvature than the other arcs; the major diameter of the blank from 5 to 6 is greater than the diameter of the finished ring by allowing for the closing of the joint plus shrinkage and turning or grinding; the diameter from 7 to 8 is greater than the diameter of the finished ring by allowing for shrinkage and the closing toward the center when the joint at 7 is closed; and the several arcs are so related .and arranged that when the finished joint is closed the ring is circular on its inside and will not need any machine work so that the scale or crust may be left on the inside surface.

The preferred first step in the process of in Fig. 2 toward the center of the blank and cuts a recess having a depth equal to about half the thickness of the blank and a width equal to half the width of the blank as'at position 2; the cutter i then moved laterally to position 3 to cut a curve concentric with the curvature of the are through the points 2, 7 and 3 of Fig. l to make an extended bearing or seating surface w; the

cutter is then moved inwardly and laterally to position 4 to make a round corner 1 and it is then moved laterally on the said curvature through the positions 5 and 6 to position 7 and makes a second opposite seating surface as, and it is then moved back to position 6 and thence to position 8' to make a second round shoulder y. The cutter C finishes its work at position 8 in Fig. 2.

The blank is then symmetrically milled or cut away on the opposite side of its median line and on the opposite side of the line, as for example at 7, where it is to be severed. The'milling of this second portion is similar to that of the first, and may be done by any suitable tool, the operations bein either simultaneous or separate as desire In the present instance I employ the lower cutter C which starting from osition l in Fig. 3 travels inwardly to position 2 to make a recess having the same dimensions a the recess made by cutter C at position 2 in Fig. 2, but symmetrically on the opposite side of the median line of the width of the blank and on the opposite side of point where the blank is severed. The cutter C is then moved to position 3 on the same carvature as that of cutter C in moving from 2 to 3 in Fig. 2, in order to cut a curve on the sameeurvature as the curvature of seat as to produce an opposite but correspondingly curved seating surface 00 and it is then moved to position 4 to form a rounded corner 3 and it is then moved on the same curvature as above described through posi- The blank is held in a' tions 5 and 6 to position 7 to make a second opposite seating surface 00 and it is thence moved from position 7 through position 6 to position 8 to make a second round corner The cutter C finishes its work at position 8 in Fig. 3, and the ring is severed by the operation. I may employ two milling or cutting tools, one for one side of the blank and the other for its opposite side, in which case they may operate: separately or simultaneously, or I may use a single cutting tool. When the milling operation is completed the parts of the joint are as shown in Fig. 4, the seating surfaces being cut on a longer radius than the radius of the are 2 to 3 but concentric with the curvature of this arc, and each end then having a recess and tongue on opposite sides of the median line of the ring, and when the ring is closed the opposite seating surfaces are on a curvature concentric with the curvature of the ring.

After the joint parts are milled the sides of the ring are ground true to the desired width. The ring is then clamped in closed position and the crust or scale on the periphery of the ring is removed by rough turning or grinding the ring to size slightly larger than the finished size. The ring is then released from the clamp, and in it natural position with its joint open but not expanded the ring is treated by being rolled between revolving rollers R R that roll the thickness of the ring to remove all strains due to its casting or to removal of its peripheral crust. This rolling sets 'the metal of the ring, which then is tempered or seasoned. The ring is then finished by closing its joint and clamping it in a cylinder whose bore equals the peripheral size prodnced by the rough grinding, when the ring in its fixed or clamped positionisremoved and its periphery is machined or ground to finished size. The ring is removed from its clamp and is then ready for use, and when in place the tongues 10 and 11 overlap as shown in Fig. 7, each projecting into an opposite recess 12 and 13 respectively, while the opposite pairs of seating surfaces as, as and :0 m co-act on the opposite sides of the median line, the recesses being deep enough to allow the tongues to lie in them with their peripheries flush with each other and on the same circumference as the body of the ring itself, and the rounded ends of the tongues and recesses cooperate when the ring is closed.

By employing an oval blank I am able to produce a ring having its inner surface on a true circle Without machining this surface and so leaving the scale or crust that is molded on this surface and which gives added stren th to the ring. The extended seating sur aces produced by milling the ring upon the curvature described provide a seal which is elongated in the circumferential line of the ring and so is greater in area or extent than the mere line or edge seal of rings now generally in use; the seating surfaces of my ring therefore present a tifghter joint against the high compression internal explosion engines where it is necessary to- Withstand sudden high pressures and to prevent excessive oil from passing the piston into the combustion chamber, and this remains true whether the ring is entirely or only partly closed. Also, the tongues of my joint are all external or on the outer surface of the ring, and are backed and confined by the cylinder wall, so that the tendency of the tongues to snap or break off which is an objection to prior rings, is obviated by my invention. I make no claim in the present application to the ring as the same forms the subject-matter of my divisional application filed November 28, 1917, and bearing Serial Number 204,310.

I claim 1. The process of forming packing rings which consists in forming an oval blank larger than the ring desired and having an are on one side of its major axis flatter than the are on its opposite side, and forming the joint at the center of said flatter are by cutting symmetrically on opposite sides of said center a shoulder and tongue in the opposite sides of said blank to a common line i and shaping their opposing seating surfaces to extend in the circumferential line of the finished ring concentric with its curvature.

' 2. The process of forming packing rings which consists in forming an oval blank larger than the ring desired and having an are on one side of its major axis flatter than the are on its opposite side, and forming the joint at the center of said flatter are by cut ting symmetrically on opposite sides of said center an inner shoulder and an external tongue in the opposite sides of said blank to its median line and shaping their opposing ing ring which consists in producing an.

oval-shaped blank larger than the ring desired, shaping the joint, rolling the blank to set the metal, tempering or seasoning the metal, compressing the blank to close the joint, and giving final shape to its periphery while the blank is under compression.

4. The process of forming a piston-packing ring which consists in producing an oval-shaped blank larger than the ring desired, shaping the joint to provide co-acting circumferentially extended seating surfaces, rolling the blank in open position to set the metal, compressing the blank to close its joint, and iving final shape to its periphery while the lank is under compression.

5. The process of forming packing-rings which consists in producing an oval blank larger than the ring desired and having a plurality of pairs of opposite arcs with the arcs of each pair adjacentto the terminals of its major axis on radii struck/from points on said axis equally ofi'set fromits center and the opposite intermediate arcs on radii struck from points on the respective farther sides of said axis and differently ofi'set from its center, and forming the joint at the center of the intermediate are having the longest radius by symmetrically cutting on'opposite sides of said center a shoulder and tongue in the opposite sides of said blank to a common line on the curvature of a radius struck from the same point as the radius of said severed are. I

In testimony whereof I aflix my signature in presence of two witnesses.

ED WARD R. NORMAN. W'itnesses:

J. MoRonnR'rs, E. H. WILCOX. 

